The invention relates to a circuit arrangement for operating an electric machine, comprising at least one high-voltage half-bridge circuit, which has a high-side semiconductor switch and a low-side semiconductor switch, wherein in each case one gate driver is assigned to the semiconductor switches for actuating said semiconductor switches, and comprising a low-voltage controller, which actuates the gate drivers.
In addition, the invention relates to a method for operating such a circuit arrangement.
Electric machines, in particular polyphase electric machines, are generally operated by an inverter, which is controlled by a microcontroller. The microcontroller is in this case arranged on the low-voltage side of the inverter, while at least one semiconductor bridge circuit is assigned to a high-voltage grid. This is known, for example, in hybrid vehicles which have a vehicle electrical distribution system with a low voltage and a drive system grid with a high voltage. The inverters generally have a plurality of half-bridge circuits, which each have two semiconductor switches, a high-side semiconductor switch and a low-side semiconductor switch which are connected in series with one another and are each actuated by a gate driver, which receives and implements control signals from the microcontroller. Output signals of the gate drivers need to be read back by the controlling microcontroller for monitoring purposes in order to ensure safe operation of the circuit arrangement or of the electric machine. Generally, in this case each actuation signal of a power switch or each output signal of a gate driver is passed separately via an insulation barrier between the high-voltage part and the low-voltage part.